The invention relates to means for mounting dental models, an attached caliper means and an articulator to permit adjustment of the articulator to a record. The invention also relates to a method for using the mounting means.
In dental restoration appliances are fabricated from models mounted on dental articulators which have provided varied capability in simulation of mandibular movement. Recent advances in articulator design have achieved precision instruments which can be adjusted for most, if not all, manidbular movements and TMJ space compression with the aid of devices for recording of mandibular movement such as checkbite records, face bows, hinge axis locators, etc.
The face bow disclosed herein incorporates a caliper like device that relates the position of the posterior area of the mandibular condyles at the level of the auditory meatus to the maxillary teeth. The face bow disclosed consists of a unique arrangement for adjusting the calipers consisting of three rods for stability and locking in their final adjustment. The calipers, in turn, provide support for a vertical main rod which has a cylindrical attachment (naison indicator) that engages the bridge of the nose over the naison suture and an adjustable, detachable, caliper support. This subassembly can be adjusted to help hold and support the calipers about the face. The vertical main rod is in turn used with a rod/fork assembly for engaging the maxillary teeth. After all measurements are obtained the calipers are removed at the detachable caliper support and the main rod is inserted into a round recess on the lower beam of the articulator. A nasion indicator is attached to the main rod of the articulator which allows recording the position of the soft tissue nasion from the facebow. A maxillary model of the patient's teeth is then placed on the rod/fork assembly and attached to the upper beam articulator ring with plaster. The lower model is related to the upper and attached to the lower beam with plaster.
Important features of this face bow are the basic design and the fact that the three rod adjustment supplies stability to the face bow and an infinite range of locking adjustment. The nasion rest is kept intact with the main rod and rod/fork of the face bow for the purpose of allowing the position of the nasion to be related to the maxillary models through additional attachments and assemblies on the articulator. Thus, through the use of a cephlometric radiograph, the soft tissue nasion can be related to other areas on models of the patient's teeth and/or gum tissues for the purpose of using cephlometric analysis to, for instance, set denture teeth and determine specific anchorage requirements for orthodontic cases, TMJ splint fabrication, bridge work, etc.
Fabrication of the final face bow appliance from filled plastics would allow the entire unit to be soaked in cold sterilizing solutions for cleaning purposes. Certain parts would be disposable to avoid cross contamination.